The present invention relates to a method of operating a vacuum processing system including two or more processing units for processing wafers and a transferring unit for carrying the wafers, wherein the wafers are processed using at least two or more of the processing units; and, the invention further relates to a vacuum processing system for carrying out the method.
A system including a plurality of processing chambers connected to a carrying chamber, for example, as disclosed in Japanese Patent Laid-open No. 133532/1988, (hereinafter referred to as the first known method) is characterized in that, in a normal operating state, different wafers can be simultaneously carried into and processed in separate processing chambers, or each wafer can be carried into and processed sequentially in two or more of the processing chambers.
Another method of operating a processing system, for example, as disclosed in Japanese Patent Laid-open No. 274746/1991, (hereinafter referred to as the second known method) is characterized in that, in a operation wherein processing steps are performed simultaneously through processing chambers along two routes, if a processing chamber located along one route is undergoing maintenance work, processing chambers located along the other route are temporarily used for all of the processing steps to be performed along the two routes.
Thus, there has been known heretofore:
a system in which wafers are subjected to a plurality of processing steps in a vacuum by carrying wafers into two or more processing chambers through a carrying passage in a vacuum atmosphere and subjecting the wafers to processing steps inherent to the individual processing chambers; a method of carrying wafers into the processing chambers; and a method wherein maintenance work is performed simultaneously with the usual wafer processing.
The first known method, described in Japanese Patent Laid-open No. 133532/1988, however, has failed to examine a situation in which a processing chamber becomes inoperable because of a failure or the like during an operation using two or more processing chambers along a processing route, to suggest that the processing should be continued under such a condition using the remaining operable processing chambers, or to consider ways of recovery of the inoperable processing chamber.
The first known method also has failed to consider a method and procedure in which, if there is a processing chamber which is required to be repaired at the time of start of an operation, the system can still be operated using only the remaining operable processing chambers.
The first known method also has failed to consider a method and procedure in which, during an operation using two or more processing chambers along a processing route, when the operation is temporarily discontinued, a process interruption using as the processing route a processing chamber not normally used for the processing route prior to the operation being discontinued is carried out in priority, and wherein the processing which was temporarily discontinued is restarted after termination of the process interruption.
The first known method also has failed to consider, during an operation using two or more of the processing units as a processing route, the situation wherein an actuating instruction is supplied to apparatuses in a processing unit not currently used for the processing route from the point of view of securing a required level of safety of an operator when an auxiliary operating unit spaced from a main operating unit supplies the actuating instruction to the apparatuses in the processing chamber not used in the processing route for the operation.
On the other hand, the second known method, described in Japanese Patent Laid-open No. 274746/1991, has failed to consider a manner of securing the safety of the operator against a processing gas flowing due to “a wrong operation” or electric shock due to improper operation of a discharging power supply when maintenance work for exchange of a target or the like is performed by an operator standing on the side of components of the working system while the usual wafer processing is being performed.
Thus, although the known methods have examined the operation performed in a state wherein processing chambers are operable and in a state where a processing chamber which needs to be repaired is initially omitted before start of operation, they have failed to consider operation in a state wherein a processing chamber become inoperable during processing due to occurrence of an abnormal state, a process interruption, a temporarily discontinued state of operation and re-start of operation from the discontinued state, and actuation and utilization of a processing chamber not used for the processing route during operation. Accordingly, the known methods have failed to consider a method of operating a system, including processing chambers of the same kind which are connected to each other, wherein, when a processing chamber becomes inoperable, the operation is continued using the remaining operable processing chambers. As a result, the previously disclosed methods have a poor working efficiency.
Further, the known methods have failed to consider ways of securing the safety of an operator in the case where recovery of an abnormal processing chamber or periodic maintenance work is performed simultaneously with the usual operation of normally processing wafers.